Discovery of Late Ordovician- Early Silurian graptolites and its Significance in Daguangba area of Hainan Island
LONG Wen-Guo;ZHOU Dai;WANG Jing;KE Xian-Zhong;ZHOU Jian-Bo;WANG Yan-Hua;Wuhan Center of China Geological Survey;Institute of Granitic Diagenesis and Metallogeny, CGS;Hainan Institute of Geological Survey;
The Ordovician-Silurian graptolites, which were identified as diplograptid, were firstly discovered in light-metamorphosed rock series in Daguangba in western Hainan Island. However, there was long-term debate on the age of the light metamorphic strata, it has been regarded as the Cambrian, Pre-Devonian, Devonian-Carboniferous, Carboniferous and Permian. The discovery of the graptolite fossils not only offered new evidences for the age of the fosils-bearing strata and further confirmed the occurrence of the late Ordovician to early Silurian strata in central-north Hainan Island, but also for Ordovician-Silurian stratigraphic division and correlation of the deep-water facies, and playing important roles in the research on paleobiogeographic provincialization, sedimentary facies and sedimentary tectonic background of Hainan Island and adjacent area.